CN112955057A

CN112955057A - Container for cooking food and corresponding enhanced thermal signaling device

Info

Publication number: CN112955057A
Application number: CN201980068774.9A
Authority: CN
Inventors: F·费龙
Original assignee: Shuangliren Balalini Italy Co ltd
Current assignee: Shuangliren Balalini Italy Co ltd
Priority date: 2018-11-16
Filing date: 2019-09-23
Publication date: 2021-06-11
Also published as: IT201800010408A1; US11963641B2; US20210378453A1; KR20210090258A; DK3880051T3; EP3880051A1; PL3880051T3; WO2020099952A1; EP3880051B1; JP2022507530A; CA3113051A1; ES2936265T3; JP7349497B2; LT3880051T

Abstract

A container for cooking food is described, the container comprising a metal body; at least one handle constrained to a portion of the metal body via a metal fixation element; at least one metal flame guard ring placed in contact with a portion of the metal body so as to provide heat conduction; and at least one thermal signal device including at least one bimetal, the at least one bimetal being formed of a first metallic material and a second metallic material having different thermal expansion coefficients from each other. The bimetal is placed in contact with a member of the cooking vessel provided with heat-conducting properties and is set for signaling the attainment of a predetermined heating value by a progressive mechanical movement related to the heating of the cooking vessel. The flame guard ring is provided with one or more through holes and the bimetal is shaped and dimensioned such that at least an indicative portion thereof is at least partially visible through the through holes at a particular temperature value.

Description

Container for cooking food and corresponding enhanced thermal signaling device

Technical Field

The present invention relates generally to a container for cooking food, and more particularly to an enhanced thermal signaling device for a container for cooking food.

Background

In the technical field of containers for cooking food, systems and devices are known for informing the user of a container for cooking food (such as a pan) of the thermal state reached by the container itself, in order to provide correct cooking and to make it possible to monitor the cooking process and to adjust the quantity of heat to be supplied. The heat supplied by gas or electricity is generally high at the beginning of use in order to bring the cooking vessel to the desired temperature, and once the desired temperature is reached, its amount should be reduced in order not to overheat the cooking vessel, which would deteriorate the quality of the cooking. Pans are typically such cooking vessels: for these cooking vessels, control of their respective thermal conditions is most critical, since such type of kitchen appliance requires thermal control, since its use at high temperatures is not inhibited by the liquid contents.

The most commonly used thermal signaling systems refer to a color change provided by a pigment that changes color when a particular temperature is reached, thereby providing visual information. There are thermochromic systems which are placed directly inside the cooking container via pigments contained in a non-stick coating placed on the inner surface of the container itself. If a change of color is expected to occur at a predetermined temperature (e.g. 180 ℃), the color will change once the predetermined temperature is reached, whereby the user can adjust the thermal power to be supplied to the cooking vessel according to his/her needs.

Thermochromic systems have two main limitations:

the pigment should be resistant to the highest cooking temperature, which may reach 300 ℃ peak. The change in color of the high temperature resistant (inorganic) pigment is very slight and difficult to detect. Identifying such a change in colour using a comparison system enabled in a more or less wide area of the bottom of the cooking vessel;

the bottom of the cooking container, where the color changing area is placed, is typically covered by the food to be cooked, in order to prevent or at least limit the view of the change of color.

These are the reasons why a thermal signalling system aimed at overcoming the above-mentioned limitations is implemented while using thermochromic pigments. In these thermal signaling systems, the thermochromic pigment is placed into a coating that coats a particular component placed in the immediate periphery of the cooking vessel. For example, if the cooking vessel is a pan, the thermochromic pigment is placed on the metal portion of the handle closest to the edge of the pan.

However, in cooking containers provided with these thermal signaling systems, the increase in temperature at the constituent parts containing the thermochromic pigments occurs after a certain time delay with respect to the increase in temperature that occurs at the cooking bottom. This occurs because it takes some time to transfer heat from the cooking base closer to the heat source to the component in question. For example, the temperature of the cooking base may be 180 ℃ while the temperature of the component containing the thermochromic pigment may not exceed 60 ℃. Thus, a pigment that changes color at a temperature of 60 ℃ will be used to signal that the cooking base reaches a temperature of 180 ℃.

The advantage of using pigments that change color at low temperatures is that the difference in color, for example from green to red, is very well defined. However, such advantages are partially offset by the heat resistance limitations of such (organic) pigments, which tend to be ineffective and do not return to their original state if cooked at temperatures in excess of 200 ℃ for long periods of time.

There are also more complex thermal signal systems based on the use of thermocouples contained inside the metal thickness of the bottom of the cooking vessel. Finally, the temperature assessed by the thermocouple is read and signaled by battery-powered electronics, which are typically placed at the end section of the handle of the cooking vessel.

Thermocouple-based thermal signaling systems have at least two major limitations:

they require complex radial drilling operations of the bottom of the cooking container in order to place the thermocouple therein;

the electronic means used to read and signal the temperature are not resistant to water and to the temperature of the dishwasher, and in any case to even accidental exposure to high temperatures (as often happens on stoves), due to its nature and to the presence of batteries.

Furthermore, thermocouple-based thermal signaling systems are expensive and hardly practical because they are required to be removable.

Finally, there are thermal signalling systems for cooking vessels based on progressive mechanical movements of specific components. This movement is obtained when a given heating value of the cooking vessel is reached. This constituent part is composed of a bimetallic strip comprising two metals having different coefficients of thermal expansion, as described for example in documents KR 2004-.

In the thermal signal systems described according to documents KR 2004-. This means that they are rather complex and less reliable mechanisms. Another thermal signalling system applied to a container for cooking food products according to the preamble of claim 1 is described in document GB 2429285 a.

Disclosure of Invention

It is therefore an object of the present invention to provide an enhanced thermal signaling device for containers for cooking food that is able to solve the above mentioned drawbacks of the prior art in an extremely simple, cost-effective and particularly functional way.

In detail, it is an object of the present invention to provide an enhanced thermal signaling device for containers for cooking food that is thermally more stable and reliable than the devices according to the prior art.

Another object of the present invention is to provide an enhanced thermal signaling device for containers for cooking food which is simpler in construction than the devices according to the prior art.

These and other objects according to the present invention are achieved by implementing a container for cooking food and a corresponding enhanced thermal signaling device as claimed in claim 1.

Further features of the invention are highlighted by the dependent claims, which are an integral part of the present disclosure.

Drawings

The characteristics and advantages of the enhanced thermal signalling device for containers for cooking food according to the present invention will be more apparent from the following description, provided for illustrative and non-limiting purposes, with reference to the attached schematic drawings, in which:

FIG. 1 is a top view of a container for cooking food that may be provided with an enhanced thermal signaling device according to the present invention;

FIG. 2 is a cross-sectional view of one embodiment of an enhanced thermal signaling device in accordance with the present invention;

FIG. 3 is a schematic diagram illustrating the principle of operation of the enhanced thermal signaling device of FIG. 2;

FIG. 4 is an enlarged view of a detail of the enhanced thermal signaling device of FIG. 2;

5A, 5B, 6A, 6B, 6C and 7 illustrate different embodiments of an enhanced thermal signaling device applied to a container for cooking food in accordance with the present invention;

FIG. 8 illustrates a possible operational configuration of one embodiment of an enhanced thermal signaling device in accordance with the present invention;

FIG. 9 illustrates a possible operational configuration of another embodiment of an enhanced thermal signaling device in accordance with the present invention;

FIG. 10 is an enlarged view of a detail of the enhanced thermal signaling device of FIG. 9;

FIGS. 11, 12 and 13 illustrate additional embodiments of enhanced thermal signaling devices in accordance with the present invention; and

fig. 14 and 15 are enlarged views of the thermal signaling device shown in fig. 12 and 13, respectively.

Detailed Description

Referring to the drawings, there is shown a container for cooking food and a corresponding enhanced thermal signaling device according to the present invention. A vessel for cooking food is generally identified by reference numeral 10 and is shown in the form of a pan for illustrative purposes only.

The cooking vessel 10 comprises a metal body 12, said metal body 12 in turn comprising a bottom wall 14 and at least one side wall 16 extending from such bottom wall 14. In the embodiment shown in the drawings, the cooking vessel 10 is a conventional pan provided with a substantially circular bottom wall 14. The pan comprises only one side wall 16, said one side wall 16 extending from the bottom wall 14, more specifically from the circular edge of the bottom wall 14. In any case, the cooking container 10 may also be provided with a plurality of side walls 16, for example the cooking container 10 may have a bottom wall 14 characterized by a quadrangular shape. Regardless of the shape of the cooking container 10, the side wall 16 extends from the bottom wall 14 in a conventional and inherently known manner so as to define an interior compartment 18 of the cooking container 10, in which interior compartment 18 food is placed for cooking.

The cooking vessel 10 further comprises at least one handle 20, preferably made of a non-metallic material. The handle 20 is constrained to the portion of the metal body 12 generally consisting of the side wall 16 via a metal fixing element 22. The handle 20 may in turn be constrained to the metal fixation element 22 by known systems, such as screws 24.

At least one metal flame guard ring 28 having a generally annular shape is disposed about the end 26 of the handle 20 at the metal securing element 22. The metal flame guard ring 28 is placed in contact with the portion of the metal body 12 that is typically comprised of the sidewall 16 to allow for thermal conduction between the metal body 12 and the metal flame guard ring 28 itself.

At least one thermal signaling device is applied inside the metal flame guard ring 28 and comprises at least one bimetallic strip 30, said bimetallic strip 30 being composed of a first strip 30A of a first metallic material and a second strip 30B of a second metallic material welded together, wherein the first metallic material and the second metallic material have different coefficients of thermal expansion. The thermal signaling means are preset for indicating the reaching of a predetermined heating value of the cooking container 10 by a progressive mechanical movement of the bimetallic strip 30 in relation to the increase of the temperature of the cooking container 10 itself, as schematically shown in fig. 3.

The first metallic material and the second metallic material may for example consist of pure aluminium having a coefficient of linear thermal expansion equal to 0.000024 deg.c and of chromium stainless steel, respectively^-1Said chromium stainless steel having a coefficient of linear thermal expansion equal to 0.000012 DEG C^-1(approximately half the coefficient of thermal expansion of aluminum). These materials are mentioned for illustrative purposes only, as the first and second metallic materials forming the bimetal 30 may even be different materials from those described above. Preferably, the ratio between the coefficient of thermal expansion of the first metallic material and the coefficient of thermal expansion of the second metallic material is at least 1.4: 1 in order to cause significant movement.

A suitably shaped bimetal 30 tends to deform when heated and "bend" around a metallic material that stretches minimally or otherwise has a low linear coefficient of thermal expansion. Thus, as shown in the schematic diagram of fig. 3, if the bimetal strip 30 is shaped substantially like an open loop or "C", the bimetal strip 30 will tend to stretch in the direction indicated by the arrow F as the temperature increases. Thus, if the open ends of the C-shape of the bimetal strip 30 are at a given distance L under ambient temperature conditions, such open ends having respective indicator portions 34 thereon will tend to be closer to each other as the temperature increases, thereby progressively reducing the distance L.

The bimetal strip 30 is placed at least partially in contact with one or more components of the cooking vessel 10 having good heat-conducting properties, such as the metal flame guard ring 28, the metal fixing element 22 and/or the screw 24 for constraining the handle 20 to the metal fixing element 22. Preferably, the heat of the cooking container 10 is transferred to the bimetal 30 via only contact with the metal flame guard ring 28. However, the metal flame guard ring 28 and the metal fixing element 22 are placed in contact with their respective portions of such a bimetal strip 30 to further ensure the transfer of heat from the cooking container 10 to the bimetal strip 30.

To adapt the configuration for signaling thermal conditions, the metal flame guard ring 28 is provided with one or more through holes, slots or windows 32, as shown in the embodiments of fig. 5A, 5B, 6A, 6B, 6C and 7. The bimetal strip 30 is shaped and dimensioned such that at least one indicating portion 34 of such bimetal strip 30 is at least partially visible (e.g. by blocking them) through the through hole, slot or window 32 at a particular temperature value. As will be better specified below, depending on the actual embodiment of the cooking vessel 10, this specific temperature value coincides with a predetermined heating value indicating an increase in the temperature of such a cooking vessel 10 or with the ambient temperature.

In order to better show that a given increment of the temperature of the cooking vessel 10 or of the predetermined heating value is reached, at least the indicating portion 34 of the bimetal 30 is coloured with a first predetermined colour, preferably red and different from the colour in which the remaining portion of said bimetal 30 is coloured. In this manner, the user can immediately recognize the thermal status by observing the through hole, slot or window 32 becoming red whenever the cooking container 10 reaches or exceeds the predetermined heating value.

In addition, steps may be taken to color the end 26 of the handle 20 in a second predetermined color, preferably green and different from the first predetermined color. Alternatively, the thermal signaling device may include at least one plate 36 placed at the through-hole, slot or window 32. The plate 36 is also coloured in a second predetermined colour, preferably green and different from the first predetermined colour in which at least the indicating portion 34 of the bimetal strip 30 is coloured. Thus, with reference to the mode of operation shown in fig. 8, the following information may be provided to the user:

the green color of the end 26 of the handle 20 or of the plate 36 can be seen through the through hole, slot or window 32 in ambient or cold conditions;

upon reaching a predetermined heating value or thermal condition greater than the ambient temperature, the through hole, slot or window 32 is blocked by the indicator portion 34, or in other words the first predetermined color (red) of the indicator portion 34 of the bimetal 30 is at least partially visible through such through hole, slot or window 32.

In the embodiments of fig. 5A, 5B, 6A, 6B, 6C and 7, in which two or more through holes, slots or windows 32 are provided, aligned with each other, the arrangement and geometry of such through holes, slots or windows 32 makes it possible to provide information about the gradual increase in temperature of the cooking container 10. In fact, as the temperature increases, the number of through holes, slots or windows 32 through which the red indicator portion 34 of the bimetal strip 30 is visible also increases. In other words, the higher the temperature of the cooking container 10, the more red surfaces of the through-holes, slots or windows 32.

The dimensions of the bimetal strip 30 and the location of the through hole, slot or window 32 are suitably designed such that a red heat signal is generated when a predetermined heating value of the cooking container 10 suitable for cooking most foods is reached. The predetermined heating value is typically above 150 ℃.

Fig. 4 schematically illustrates the bimetal strip 30 having the shape of an open ring or C-ring, wherein a first strip 30A of the first metallic material has a coefficient of thermal expansion that is greater than a coefficient of thermal expansion of a second strip 30B of the second metallic material. In addition, a first strip 30A of a first metallic material is placed on the outer surface of the open ring. The thickness of the first and second metallic materials constituting the bimetal is relatively small in order to obtain a more pronounced movement of the bimetal 30 itself. Preferably, the first strip of the first metallic material 30A has a thickness greater than a thickness of the second strip of the second metallic material 30B. For example, in the case of the aforementioned metallic material, the first aluminum strip 30A may have a thickness in the range of 0.2mm to 0.3mm, and the second steel strip 30B may have a thickness in the range of 0.1mm to 0.15 mm.

In the case of metallic materials with different properties, for example in the case where the two metallic materials consist of steels with different coefficients of thermal expansion, the thicknesses of such metallic materials are suitably and reciprocally calibrated and may cause significant movements even with reduced overall thicknesses (for example of the order of 0.2 mm).

Fig. 8 shows the configuration of the bimetal 30 at ambient temperature on the left side of the cross section of the handle 20, with the plate 36 visible through the through hole, slot or window 32. In contrast, the right side of the cross-section of the handle 20 shows the configuration of the bimetal 30 when the predetermined heating value is reached, wherein the indicator portion 34 is visible through the through hole, slot or window 32 due to the closing movement of the ring constituting the bimetal 30 itself.

Obviously, the bimetal 30 may be implemented such that the metallic material is reversed with respect to the position shown in fig. 4. In fact, fig. 9 and 10 schematically illustrate the bimetal 30 having the shape of an open ring or C-ring, wherein the first strip 30A of the first metallic material has a coefficient of thermal expansion which is still greater than the coefficient of thermal expansion of the second strip 30B of the second metallic material. However, here a first strip 30A of a first metallic material is placed on the inner surface of the open ring. In this case, the ring expands due to the heating. In other words, if the open ends of the C-shaped bimetal 30 were at a given distance L under ambient temperature conditions, such open ends would tend to move away from each other as the temperature increases, thereby gradually increasing the distance L. According to this operating configuration, as the temperature increases, the bimetal 30 progressively disengages its own indicator portion 34 from the through hole, slot or window 32.

Thus, according to this operating configuration, in order to signal the attainment of a predetermined calorific value, it is sufficient to color the plate 36 or the end 26 of the handle 20 in a first predetermined color, preferably red. Instead, the indicator portion 34 of the bimetal strip 30 will be coloured a second predetermined colour, preferably green. In this case, the second predetermined color (green) of the indicator portion 34 of the bimetal strip 30 will be at least partially visible through the through hole, slot or window 32 under ambient temperature conditions. Alternatively, the indicator portion 34 of the bimetal strip 30 may be devoid of any particular colour, so that under ambient temperature conditions only the natural colour of the second metallic material forming the second strip 30B of such bimetal strip 30 (which is distinctly different from the first predetermined colour of the plate 36) will be visible through the through-hole, slot or window 36.

Thus, whenever the bimetal 30 expands due to thermal effects, it is the first predetermined colour (red) of the plate 36 beneath it that is at least partially visible through the through hole, slot or window 32. This operating configuration of the bimetal 30 is illustrated in fig. 9, in which the configuration of the bimetal 30 at ambient temperature is shown on the right side of the section of the handle 20 (the second predetermined colour of the indicator portion 34 of the bimetal 30 is visible), while the configuration of the bimetal 30 when a predetermined heating value is reached (the first predetermined colour of the plate 36 is visible), in which the opening movement of the ring constituting the bimetal 30 itself is shown, is shown on the left side of the section of the handle 20.

An alternative way of using the deformation of the bimetal 30 to signal a given thermal condition is shown in fig. 11 to 13. In these embodiments, the indicator portion 34 of the bimetal blade 30 is provided with a respective projection 38, said projection 38 being predisposed to rise through the respective through hole, slot or window 32 when a predetermined heating value is reached. In other words, under the hot conditions of cooking vessel 10, protrusions 38 come out and are at least partially visible through-holes, slots or windows 32 drilled in metal flame guard ring 28. Instead, these protrusions 38 remain hidden under ambient temperature conditions or in any case there is a temperature below said predetermined calorific value.

Thus, in this operating configuration of the bimetal 30, the attainment of a predetermined heating value is signaled by the projection 38 coming out of the through hole, slot or window 32 made on the metal flame guard ring 28. The surface of the protrusion 38 may conveniently be coloured in a predetermined colour, preferably red, to indicate the thermal status of the cooking container 10. Fig. 11 and 12 show on one side the ambient temperature configuration (with the projections 38 hidden) and on the other side the configuration when the predetermined heating value is reached (with the projections 38 protruding through their respective through holes, slots or windows 32).

As shown in fig. 14 and 15, each protrusion 38 of the bimetal 30 may be obtained at the respective indicating portion 34 by a drawing process or by applying an additional element (which constitutes only the respective protrusion 38) to each indicating portion 34.

In the embodiment shown in fig. 12, the bimetal 30 has a substantially arcuate shape. In contrast, in the embodiment shown in fig. 13, the bimetal 30 is provided with an inner elongated substantially U-shaped portion 40, said substantially U-shaped portion 40 being placed at least in contact with the metal fixing element 22 and acting as a movement amplification ring of the bimetal 30. The inner portion 40 enables the bimetal strip 30 to have a significant movement compared to the reduced size of the bimetal strip 30 itself. In addition, as shown in fig. 13, the bimetal 30 of fig. 12 may be in contact with both the metal flame guard ring 28 and the metal fixing element 22, and further with the screw 24 that constrains the handle 20 to the metal fixing element 22.

Independently of the embodiment of the bimetal 30 described above, it is worth emphasizing that the bimetal-based thermal signalling device is physically reversible. Thus, each time the cooking vessel 10 cools, the bimetal 30 returns to its own initial condition, normally specified for the ambient temperature, and is again ready for use.

Thus, it has been proved that the thermal signalling device for containers for cooking food according to the present invention achieves the objects previously highlighted and in particular provides the following advantages:

the movement of the bimetal (in essence, mechanical movement) provides repeatability, reliability and stability;

absence of variable elements, such as thermochromic pigments or electronic circuits;

if any (red, green) signal coatings are used, they may be chosen from high temperature stable coatings;

the thermal signaling device comprises simple and easy-to-manufacture elements and its reduced size facilitates cost control;

the thermal signaling means can be designed for a faster or slower response by varying the material/thickness combination of the strip of metallic material forming the bimetallic strip;

a progressive temperature indication can be provided.

The thermal signalling device thus conceived, according to the container for cooking food of the present invention, can in any case have numerous modifications and variants, all falling within the same inventive concept; moreover, all the details may be replaced by technically equivalent elements. In practice, the materials used, as well as the shapes and dimensions, may be any according to the technical requirements.

The scope of the invention is therefore indicated by the appended claims.

Claims

1. A container (10) for cooking food, comprising:

-a metal body (12), said metal body (12) in turn comprising a bottom wall (14) and at least one side wall (16), wherein said side wall (16) extends from said bottom wall (14) to define an internal compartment (18) of said cooking container (10), in which internal compartment (18) food is arranged for cooking;

-at least one handle (20), said at least one handle (20) being constrained to a portion of said metal body (12) by means of a metal fixing element (22);

-at least one metal flame guard ring (28) having a substantially annular shape, said at least one metal flame guard ring (28) being arranged around an end (26) of the handle (20) at the metal fixing element (22), said metal flame guard ring (28) being placed in contact with a portion of the metal body (12) to allow heat conduction between the metal body (12) and the metal flame guard ring (28); and

-at least one thermal signalling device comprising at least one bimetallic strip (30),

wherein the bimetal strip (30) is placed at least partially in contact with one or more members (22; 24; 28) of the cooking container (10) having thermal conductivity, wherein the thermal signaling means is arranged to signal reaching a preset thermal value of the cooking container (10) by means of a progressive mechanical movement of the bimetal strip (30) related to the heating of the cooking container (10), and wherein the metal flame guard ring (28) is provided with one or more through holes, slots or windows (32), the cooking container (10) being characterized in that the bimetal strip (30) consists of a first strip (30A) of a first metallic material and a second strip (30B) of a second metallic material welded together, the first and second metallic materials having different coefficients of thermal expansion, and in that the bimetal strip (30) is shaped and dimensioned such that at least one of the bimetal strips (30) is The indicator portions (34, 38) are at least partially visible through the through-holes, slots or windows (32) at a particular temperature value.

2. Cooking container (10) according to claim 1, characterized in that said bimetallic strip (30) has the shape of an open ring or of a substantially arched ring.

3. Cooking container (10) according to claim 2, characterized in that said first strip (30A) of said first metallic material has a thermal expansion coefficient greater than that of said second strip (30B) of said second metallic material, said first strip (30A) of said first metallic material being placed on the outer surface of said open ring, so that the open ends of said open ring provided with respective indication portions (34) tend to be closer to each other as the temperature increases, blocking said through holes, slots or windows (32).

4. Cooking container (10) according to claim 3, characterized in that at least the indicator portion (34) of the bimetal strip (30) is coloured in a first predetermined colour, the first predetermined colour is preferably red and is different from the colour in which the remainder of the bimetal (30) is coloured, said first predetermined color being at least partially visible through said through-hole, slot or window (32) upon reaching said preset heat value, and wherein the end (26) of the handle (20) is coloured in a second predetermined colour, the second predetermined color is preferably green and different from the first predetermined color, the second predetermined color being at least partially visible through the through hole, slot or window (32) under ambient temperature conditions, i.e. when the indicator portion (34) does not block the through hole, slot or window (32).

5. Cooking container (10) according to claim 2, characterized in that said first strip (30A) of said first metallic material has a thermal expansion coefficient greater than that of said second strip (30B) of said second metallic material, said first strip (30A) of said first metallic material being placed on the inner surface of said open ring, so that the open end of said open ring provided with the respective indicator portion (34) tends to move away with the increase of temperature, opening said through holes, slots or windows (32).

6. Cooking container (10) according to claim 5, characterized in that at least the indicator portion (34) of the bimetal (30) is coloured a second predetermined colour, preferably green and different from the colour with which the rest of the bimetal (30) is coloured, which is at least partially visible through the through hole, slot or window (32) under ambient temperature conditions, and in that the thermal signalling means comprise at least one plate (36) placed at the through hole, slot or window (32), the plate (36) being coloured a first predetermined colour, preferably red and different from the second predetermined colour, which first predetermined colour, when the preset calorific value is reached, i.e. when the indicator portion (34) does not block the through hole, The slot or window (32) is at least partially visible through the through hole, slot or window (32).

7. Cooking container (10) according to claim 5, characterized in that the indicator portion (34) of the bimetal strip (30) does not have any specific colour, such that, under ambient temperature conditions, only the natural color of the second metallic material forming the second strip (30B) of the bi-metallic strip (30) is visible through the through-hole, slot or window (36), and the thermal signaling means comprises at least one plate (36) located at the through-hole, slot or window (32), the plate (36) is coloured in a first predetermined colour, preferably red and different from the natural colour, the first predetermined color is at least partially visible through the through hole, slot or window (32) when the preset heating value is reached, i.e. when the indication portion (34) does not block the through hole, slot or window (32).

8. Cooking container (10) according to any one of claims 1 to 7, characterized in that the cooking container (10) comprises two or more through holes, slots or windows (32) aligned with each other, so that as the temperature increases, the number of said through holes, slots or windows (32) through which the coloured indication portion (34) is visible increases, the arrangement and geometry of said through holes, slots or windows (32) thus allowing to provide information about the gradual increase of the temperature of the cooking container (10).

9. Cooking container (10) according to claim 1, characterized in that said bimetallic strip (30) is provided with an elongated, substantially U-shaped inner portion (40), said inner portion (40) being placed in contact with at least said metal fixing element (22) and acting as a movement amplification ring of said bimetallic strip (30).

10. Cooking container (10) according to any of claims 1 to 9, characterized in that the ratio between the coefficient of thermal expansion of the first metallic material and the coefficient of thermal expansion of the second metallic material is at least 1.4: 1.

11. cooking container (10) according to any of claims 1 to 10, characterized in that the first and second metallic materials are aluminum and steel, respectively.

12. Cooking vessel (10) according to any of claims 1 to 11, characterized in that the first strip (30A) of the first metallic material has a thickness greater than the thickness of the second strip (30B) of the second metallic material.

13. Cooking vessel (10) according to any of claims 1 to 12, characterized in that the member (22; 28) of the cooking vessel (10) having good heat conductive properties is selected from the group comprising one or more of the following:

-a metal flame guard ring (28);

-a metallic fixation element (22);

-a screw (24), said screw (24) fastening said handle (20) to said metal fixation element (22).

14. Cooking container (10) according to any one of claims 1 to 13, characterized in that said indication portion (34) of said bimetallic strip (30) is provided with a respective protrusion (38), said protrusion (38) being arranged to be lifted upon reaching said preset calorific value and to be at least partially visible through a respective through hole, slot or window (32).

15. Cooking container (10) according to claim 14, characterized in that the surface of the protrusion (38) is coloured in a predetermined colour, preferably red, to indicate the thermal status of the cooking container (10).

16. Cooking container (10) according to claim 14 or 15, characterized in that each of said projections (38) is obtained at the respective indicator portion (34) by a drawing process.

17. Cooking container (10) according to claim 14 or 15, characterized in that each of said projections (38) is obtained by applying a further element onto said indicator portion (34), each further element forming a respective projection (38).